In a peening device, for example, pins which are impact means are moved back and forth by an ultrasonic vibration to impact on a surface to be worked of a workpiece (sheet metal or the like), compressive residual stress is generated on the surface to be worked, and thus, improvement in bending forming (peen forming) of the workpiece, or improvement in fatigue characteristics of the workpiece or a welding portion thereof is achieved.
When the peening device is manually operated and peening is performed on the surface to be worked, a worker directly receives the vibration due to a back and forth motion of pins. Accordingly, in the peening device in the related art, there is a problem that stability of peening processing deteriorates due to vibration or there is problem that variation arises in an impact angle caused by a worker.
In order to solve the above-described problems, in PTL 1, a structure is disclosed in which a peening device main body is held to be perpendicular to a surface to be worked, and vibration is absorbed by a spring.
In addition, in PTL 2, a device is disclosed in which a peening device main body is held by a holding mechanism such as a robot, the holding mechanism such as a robot and a surface to be worked are positioned to be perpendicular to each other, and the surface to be worked is automatically impacted while being pressed to a welding bead portion.